when i was into plants all i used was sand in the end and with great results, daltons propagating sand which you find at bunnings mitre 10 or all farms cheap to, bout 6-8bux per large bag,
I just add straight sand to tank before the water and have water slowly fill the tank then do a couple of large waterchanges turn filter on and water will clear up pretty quick :lol:
like alan i never really stirred it up as imo no real need to if well planted as the roots along with the bacteria in the sand (after time) and preferably a filter should all work in well together and balance everything, if you get a build up on the surface you could gravel vac just the top, hope that makes sence lol